Generally speaking, such slide rails comprise, as is described in document WO 97/03860:
a fixed section, intended to be fixed to the vehicle, PA1 a mobile section, which is sliding mounted along the fixed section and which is intended to be fixed to the seat to allow this seat to move in a so-called longitudinal direction, forwards and backwards, at least the fixed section being of U-shaped transverse section having a web and two flanges, the two sections defining an inner volume, the two flanges of the fixed section being folded towards each other and ending in a hook-shaped return turned inwards from the fixed section and downwards, and the mobile section sliding longitudinally between the two flanges of the fixed section, PA1 a slide rail catch which is movable between on the one hand, a locked position where said catch immobilises the two sections relative to each other and on the other hand, an unlocked position where said catch allows the mobile section to slide, the slide rail catch being brought resiliently towards its locked position, PA1 and a memorisation runner which is sliding mounted relative to the fixed section parallel to the longitudinal direction, this runner being placed outside the inner volume of the slide rail, PA1 an attachment device of the memorisation runner which is movable between on the one hand, an attached position where said attachment device fixes the memorisation runner to the mobile section and on the other hand, an unattached position where said attachment device does not fix the memorisation runner to the mobile section, PA1 first control means adapted to move the slide rail catch from its locked position to its unlocked position so as to allow the mobile section to slide forwards without the memorisation runner moving, this memorisation runner then restricting the backward movement of the mobile section while defining a memorised position of the mobile section, PA1 and second control means adapted to move simultaneously the slide rail catch from its locked position to its unlocked position and the attachment device from its unattached position to its attached position, so as to allow the mobile section and the memorisation runner to slide simultaneously relative to the fixed section, either forwards or backwards, in order to adjust the memorised position of the seat. PA1 in that the memorisation runner engages by fitting with a single flange of the fixed section, PA1 in that a runner catch is carried by the memorisation runner and is movable between on the one hand, a locked position where said runner catch immobilises the memorisation runner relative to the fixed section and on the other hand, an unlocked position where said runner catch does not immobilise the memorisation runner, the runner catch being in the locked position at least when the mobile section returns to the memorised position, PA1 and in that the flange carrying the memorisation runner comprises notches with which the memorisation runner catch engages when the runner catch is in the locked position. PA1 the notches are carried by the hook-shaped return of the flange carrying the memorisation runner; PA1 the runner catch is brought resiliently to its locked position by a spring mounted on the memorisation runner with the result that in the unattached position of the attachment device, the memorisation runner is locked on the fixed section; PA1 the attachment device is brought resiliently to its unattached position; PA1 the first control means move the attachment device into its unattached position simultaneously with the movement of the slide rail catch from its locked position to its unlocked position to allow the mobile section to slide forwards without the memorisation runner moving; PA1 the attachment device is mounted on the second control means; PA1 the first and second control means are mounted on a support part integral with the mobile section and the first control means activate the second control means to move the slide rail catch from its locked position towards its unlocked position; PA1 the support part carries a pawl which is mounted moving between an engaged position where it engages with the second control means to hold the slide rail catch in its unlocked position when the mobile section slides forwards or backwards without the memorisation runner moving, and a disengaged position where it abuts against the memorisation runner; PA1 the mobile section is of inverted U-shaped transverse section having a web and two flanges which extend outwards and upwards by a return which is engaged under the hook-shaped return of the fixed section, the support part including a web fixed to the web of the mobile section and an overlap extending parallel to the flange of the fixed section which carries the memorisation runner, a stop pin projecting from the web of the support part to abut, simultaneously with the pawl, against the memorisation runner, when the mobile section returns to the memorised position; PA1 the first means comprise a control arm rotary mounted on the support part web, and a rod rotating integrally with said arm, said rod having a nose and a pin which engage respectively with the second control means and the attachment device; PA1 the second control means comprise a flank extending approximately parallel to the overlap of the support part being rotary mounted on this overlap, a rear end of said flank supporting a lug extending transversally above the web of the mobile section so as to be in contact with the slide rail catch; PA1 the memorisation runner carries on the one hand, a side wedge fitted with a back stop which is extended by an inclined surface downwards and forwards and on the other hand, a rotary longitudinal arm a front end of which carries the runner catch and a rear end of which is curved on the opposite side from the fixed section; and PA1 the attachment device of the runner includes a lever rotary mounted approximately on the rear end of the flank of the second control means and a front end of which has a ramp engaging with the rod pin of the first control means so that the rotary motion of said rod causes a reverse rotation of the attachment device, and the rear end of which has on the one hand, a tracker pin downward pointing so as to engage with the side wedge of the runner and to the rear of which projects a support surface located at the base of the curved rear end of the memorisation runner arm, so that when the runner moves, the support surface engages said curved rear end and the tracker pin is supported against the stop of the runner wedge.
To access the rear seats of such a vehicle, a passenger activates the first control means, generally with the seat back folding down forwards, then slides the seat towards the front of the vehicle to a stop position. The seat is then put back into its initial position by sliding it towards the rear of the vehicle to its so-called memorised initial position, marked by the memorisation runner.
In the slide rail of the above-mentioned type disclosed by the document WO 97/03860, the memorisation runner is straightforwardly slidingly mounted on the fixed section parallel to the vehicle longitudinal direction without being positively locked on this section when the seat is returned to its initial position. Consequently, mishandling the seat or wear in the memorisation runner may lead to the untimely movement of the memorisation runner and therefore to faulty repositioning of the seat in a displaced position relative to the initial position.